High risk of tuberculosis in systemic lupus erythematosus?

Abstract

The incidence and severity of tuberculosis (TB) in patients with systemic lupus erythematosus (SLE) varies greatly among different series. In addition, prospective data are scarce. The aim of this study is to analyse the frequency and severity of TB in our cohort of lupus patients. We analysed data from a prospective database of a single center cohort of 232 patients with SLE (ACR criteria). Prophylaxis with isoniazid was not regularly administered. We identified all cases of TB diagnosed during 10 years (January 1994 to December 2003). The following variables were analysed: annual incidence of TB, location of infection and response to therapy. Data from published series reporting on the incidence of TB among SLE patients were extracted.

Three patients (1.3%) suffered clinically manifest TB in 1603 patient-years of follow-up, resulting in an incidence of 187 cases/100 000 patient-years (95% CI 39-547). The pooled annual incidence of TB infection in our area during this period was 30/100 000 individuals. We recorded two cases of pulmonary TB and one case of tuberculous pleurisy. All patients had good response to therapy. The annual incidence of TB among SLE patients in other series, most of them from developing countries, varied between 150/100 000 patients in Turkey and 2450/100 000 patients in India. Of note, high prevalence of extrapulmonary forms as well as elevated TB-associated mortality was reported in most series.

TB was more frequent in SLE patients than expected in the general population. We did not see any cases of disseminated infection and all patients had good response to treatment. Our data compare favourably in terms of incidence, severity and outcome with those from highly endemic areas.